Yes, people DO survive this. Flappy and I marked our 13th anniversary this past Sunday (4 February), and there are folks here on the site who've made it even longer.
There's a lot of waiting involved here. Waiting for appointments, for results, for surgeries, et c., et c. Like Tom Petty used to say, the waiting IS the hardest part.
We've all been where you are now, and it sucks (sorry to be indelicate). Not being able to sleep makes the pain and fear worse; when you're hurting and scared, rest is all but impossible. In my case, the drugs they gave me to ease the pain in my ear did absolutely nothing.
You said you can't eat. Is this because of the pain, or because you have no appetite? The tumor on my tongue made it really hard to move food around in my mouth, so if I had anything firmer than macaroni and cheese, or mashed potatoes and gravy, I'd tear off a chunk of whatever I was eating, put it in my mouth and swallow. I called it snake eating. What I could eat was soup, scramble eggs, stuff like that. I also quit coffee temporarily--it irritated my tumor. Chai latte made with soy milk helped a lot. It gave me calories, the warm soy milk was comforting, and the cloves soothed my tongue.
Have you asked your doctor if he (or she) knows of any support groups for oral cancer in your area? I've found that the folks here on the site are really friendly and helpful. I wish I'd known about it when my trip started.
Please let us know how things are going for you.